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Old 09-03-2008, 03:47 PM   #1
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Default Handling difference: Rear Dog-bone vs 'CVD' type

For what reason would I want one or the other?

What is the handling difference?
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Old 09-03-2008, 04:00 PM   #2
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For what reason would I want one or the other?

What is the handling difference?

I have tried CVDs in the front and rear and there is no handling difference. I usually run dog bones in the back because I could not find any reason to spend the money for rear CVDs.

The front is another matter. In an accident it is very easy to knock the front dog bone out and when this happens about 1/4 of the time I would loose the front drive cup too. Once I put CVDs in the front I never had them pop out and never lost another drive cup. The front CVD is a very good investment.

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Old 09-03-2008, 04:28 PM   #3
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good question!!!

anyone???
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Old 09-03-2008, 04:38 PM   #4
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Front CVD's make sense due to not only the up and down motion but the side to side motion of the front upright while steering. With CVD's you avoid the risk of any kind of binding that can occur with dogbones. Rear suspension only has up and down motion so the risk of binding with the rear dogbones isn't very likely.
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Old 09-03-2008, 06:21 PM   #5
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on this one, we will need the help from SALVEN, TOSO, MORGANTI, COLLARI, FUKUDA, or any top end developer driver.... even HUDY can be a good...
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Old 09-03-2008, 09:25 PM   #6
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Rear cvd's will give you more rear traction than dogbones. Yes, you also will not loose them in a wreck. Most importantly, more rear traction! Hope this helps!
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Old 09-03-2008, 09:30 PM   #7
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From my offroad days, it has always been explained that CVD want to straighten themselves. So when the suspension compresses, the CVD will be trying to straighten out, I guess meaning trying to uncompress the suspension so they can be straight. But with that said, I have no idea what that means for handling.
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Old 09-04-2008, 01:07 AM   #8
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Rear cvd's will give you more rear traction than dogbones. Yes, you also will not loose them in a wreck. Most importantly, more rear traction! Hope this helps!
I'm sorry but how do rear cvd's give more rear traction. I run cvd's up front (because i run a spool) and dogbones in the rear. But i think it would be very hard to notice the difference between rear dogbones and cvd's.
Winner's circle pretty much summed it up i think

But then again i may be wrong
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Old 09-04-2008, 05:26 AM   #9
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Due to the nature of the construction of cvd's there's generally less slop in the drive train. Throttle response input is more direct to the drive wheels. Other than that I can't see how they would improve handling except for better throttle response to drive wheels.
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Old 09-04-2008, 11:00 AM   #10
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I remember in electric off-road the bones would tend to 'lock' the suspension at the point they where when you hit the power, whereas the cvd would have alittle more give and soak the bumps better on power...now sliders, they really float

question is: if we all seem to think cvd type is better why do the top guys run rear bones?
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Old 09-04-2008, 12:41 PM   #11
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If the Universal wants to stay straight as it spins then wouldn't that provide some kind of resistance against compressing the suspension? If the suspension compresses slower then the weight transfer would be slower. That would make you think that the dogbones allow the suspension to compress/transfer weight faster to gain more traction.
Isn't that why electric sedans have adjustment to raise and lower the diffs so you can get different universal angles for adjusting on power traction??

The big question is if it makes enough of a difference to notice.
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Old 09-04-2008, 01:23 PM   #12
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I would ask this question in the offroad electric areas. I remember when I ran offroad electric ALL the top drivers ran CVD's in the front and dogbones in the rear. I remember when I asked guys like Francis and Drake etc why their answer was always... "The rear end squares up faster". The bad part of this story is I don't remember what the heck that means. I do know that most if not all top racers do run CVD's in the front and dogbones in the back. It could be a serious case of me too syndrome, but there could be a legit reason.

Dogbones are less expensive and require less maintenance.
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Old 09-04-2008, 09:38 PM   #13
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With a extensive back ground in full size car racing and a reasonable amount of RC here is my $.02. CVD stands for Constant Velocity Joint. As a transmission joint rotates, when out of alignment, the fulcrums of the joint cause the shaft speed to increase and slow down per rotation. This can be proven mathematically and if you Google enough I'm sure you will find this proven somewhere but you better be up on your calculus. In a joint or dog bone this happens twice and the speed change is greater. The more joints the less the speed changes will be. True constant velocity is not a mathematical possibility but the more the better, this is why in full size cars these have multi ball drive CVD systems, the more balls the more constant the speed changes will be. The down side in what we do in RC is that shaft length changes are more limited with CVD's due to only have one sliding joint. Real cars will have splinted slip joints on the axles and CVD on both ends of the axle (the best way to do things). The reason we see fewer CVD in off-road is most likely due to the requirements of geometry do to large suspension travel. Joby is correct that CVD with their more consistent speed will increase grip.
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Old 09-05-2008, 06:16 PM   #14
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Thank you Robert. We have done research on this, and what we have found is that you will gain traction every time when you change from bones to cvds! I cannot explain why or how, but, it does. Try it and find out for yourself.
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Old 09-05-2008, 07:14 PM   #15
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i was to understand that rear dogbones helped with rear traction due to the friction taking away some of the "punch",kind of like a heavy flywheel.with that said,it also seems like the friction would affect the suspension as well,which might negate the effect.i just dissproved my theory maybe.wtf?
anyway i think the advantage would be less wear and less binding once the wear occurs,and you dont lose them in a crash.
i do however disagree with the "complex"angle of the front end .the angle of the drive .the angle of the dangle really only increases if the steering angle degree is more than the suspension arm angle.yes it is more likely to occur in the front end than the rear end.i think it would change the "thrust"angle.i dont know the right term for it,but when the angle of the front tires change,it changes the direction of the force that wants to straighten out the dogbone or cvd.
not wanting to ruffle any feathers,just some food for thought.i am pretty positive that i wouldnt be able to tell the difference,but i dont race onroad,yet.just offroad.it would take more than dogbone bind to slow me(well,my throttle finger)down...
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